Question: Simplify the expression. $(-5r-1)(5r-8)$
Explanation: First distribute the ${-5r-1}$ onto the ${5r}$ and ${-8}$ $ = {5r}({-5r-1}) + {-8}({-5r-1})$ Then distribute the ${5r}.$ $ = ({5r} \times {-5r}) + ({5r} \times {-1}) + {-8}({-5r-1})$ $ = -25r^{2} - 5r + {-8}({-5r-1})$ Then distribute the ${-8}$ $ = -25r^{2} - 5r + ({-8} \times {-5r}) + ({-8} \times {-1})$ $ = -25r^{2} - 5r + 40r + 8$ Finally, combine the $x$ terms. $ = -25r^{2} + 35r + 8$